Portable radial stackers have been used for many years to stack bulk materials such as aggregate for road construction, grain and coal. Radial stackers, which swing around in a radius to stack material in an arc, permit substantially more material to be stacked than is possible using a conventional stationary stacker that permits only a conical stack. Telescoping radial stackers permit even more material to be stacked as the stacker is extended or retracted during conveying operations.
Radial stackers typically include a wheeled axle disposed between a hopper and the top of the stacker from which the material is discharged. These wheels permit the stacker to be swung in an arc, with the hopper including a pivot plate on which the stacker pivots.
An additional advantage of having a wheeled radial stacker is that the stacker may be folded over itself and be ready for road transport in relatively little time, as the wheels that are used for radial travel can be displaced into a position aligned with the stacker to support the stacker for travel.
In recent years, tracked drives have been used in quarries, agricultural and mining operations to enable equipment to be moved over harsh terrain for ideal positioning for stacking operations. While tracked vehicles have proven to be of great benefit for such purposes, the use of tracks instead of wheels makes it more difficult to shift a stacker radially to facilitate the stacking of material in an arc instead of a cone. Also, because tracked vehicles are not typically permitted to be driven on road surfaces, they are normally loaded onto flatbed trucks for transit from one work site to another. These two drawbacks with the use of tracks has to a certain extent limited the use of tracked vehicles.